U.S. patent number 10,658,598 [Application Number 15/525,202] was granted by the patent office on 2020-05-19 for fluorinated aromatic small molecules as functional additives for dispersion of conductive polymers.
This patent grant is currently assigned to HERAEUS DEUTSCHLAND GMBH & CO. KG.. The grantee listed for this patent is Heraeus Deutschland GmbH & Co. KG. Invention is credited to Andreas Elschner, Nina Kausch-Busies, Yuriy N. Kononevich, Wilfried Lovenich, Sergei A. Ponomarenko, Alexey S. Tereshchenko.
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United States Patent |
10,658,598 |
Lovenich , et al. |
May 19, 2020 |
Fluorinated aromatic small molecules as functional additives for
dispersion of conductive polymers
Abstract
The present invention relates to a compound having a general
formula selected from the group consisting of formula 1a and 1b,
wherein K represents an aromatic or heteroaromatic group in which
at least one hydrogen atom may be substituted by a functional
groups selected from the group consisting of a sulfonic acid group,
a sulfuric acid group, an ammonium group and an aliphatic group; X
is selected from the group consisting of a C--C-bond, O, S,
SO.sub.2 and NR', wherein R' represents a hydrogen or an aliphatic
or aromatic group; A represents a fluorinated or perfluorinated
aromatic group; n represents an integer in the range from 2 to 6; m
represents an integer in the range from 1 to 3. The present
invention also relates to a composition comprising this compound,
to a process for the preparation of a conductive layer using this
composition, to a conductive layer comprising the compound
according to the present invention, to electronic components
comprising this conductive layer and to the use of the compound
according to the present invention as an additive in a
hole-injection layer of an OLED or in an organic solar cell.
##STR00001##
Inventors: |
Lovenich; Wilfried
(Bergisch-Gladbach, DE), Kausch-Busies; Nina
(Bergisch Gladbach, DE), Ponomarenko; Sergei A.
(Moskau, RU), Elschner; Andreas (Mulheim,
DE), Kononevich; Yuriy N. (Moskau, RU),
Tereshchenko; Alexey S. (Moskau, RU) |
Applicant: |
Name |
City |
State |
Country |
Type |
Heraeus Deutschland GmbH & Co. KG |
Hanau |
N/A |
DE |
|
|
Assignee: |
HERAEUS DEUTSCHLAND GMBH & CO.
KG. (Hanau, DE)
|
Family
ID: |
51900354 |
Appl.
No.: |
15/525,202 |
Filed: |
November 17, 2015 |
PCT
Filed: |
November 17, 2015 |
PCT No.: |
PCT/EP2015/076868 |
371(c)(1),(2),(4) Date: |
May 08, 2017 |
PCT
Pub. No.: |
WO2016/079144 |
PCT
Pub. Date: |
May 26, 2016 |
Prior Publication Data
|
|
|
|
Document
Identifier |
Publication Date |
|
US 20170365798 A1 |
Dec 21, 2017 |
|
Foreign Application Priority Data
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|
|
|
|
Nov 18, 2014 [EP] |
|
|
14193716 |
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H01L
51/0037 (20130101); C07D 321/10 (20130101); H01L
51/0052 (20130101); C07C 43/29 (20130101); H01L
51/0073 (20130101); H01L 51/005 (20130101); C07C
309/43 (20130101); H01L 51/5088 (20130101); Y02E
10/549 (20130101); H01L 51/42 (20130101) |
Current International
Class: |
H01L
51/50 (20060101); H01L 51/00 (20060101); C07C
43/29 (20060101); C07D 321/10 (20060101); C07C
309/43 (20060101); H01L 51/42 (20060101) |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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|
|
|
|
|
|
1405849 |
|
Apr 2004 |
|
EP |
|
1640372 |
|
Mar 2006 |
|
EP |
|
2006-22210 |
|
Aug 2006 |
|
JP |
|
2006222010 |
|
Aug 2006 |
|
JP |
|
2007176921 |
|
Jul 2007 |
|
JP |
|
Other References
Yang Liu, et al., Novel Sulfonated Thin-Film Composite
Nonfiltration Membranes with Improved Water Flux for Treatment of
Dye Soluitions, Journal of Membrane 194-195 Science, 2012, 218-229.
cited by applicant .
Cuibo Liu, et al., Selective C4-F Bond Cleavage/C-O Bond Formation
of Polyfloruoarenes with Phenols and Benzyl Alcohols, Journael of
Fluorine Chemistry 156, 2013, 51-60. cited by applicant .
International Search Report issued in PCT/EP2015/076868 dated Apr.
6, 2016. cited by applicant .
Jarman et al, "Octafluorotoluene as a Reagent for the Selective
Protection of Alcoholic and Phenolic Functions: Synthesis and
Cleavage of Perfluorotolyl and Other Perfluoroaryl Ethers of
Steroids and Other Model Compounds", J. Chem Research (S), 1985,
pp. 114-115. cited by applicant .
Yang et al, "Fluorinated Naphthalocyanines Displaying Simultaneous
Reverse Saturable Absorption at 532 and 1064 nm", Advanced
Materials, 2005, vol. 17, No. 7, pp. 875-879. cited by
applicant.
|
Primary Examiner: Clark; Gregory D
Attorney, Agent or Firm: Blank Rome LLP
Claims
The invention claimed is:
1. A composition comprising I) at least one conductive polymer,
wherein the conductive polymer comprises a complex of
poly(3,4-ethylenedioxythiophene) (PEDOT) and polystyrenesulfonic
acid (PSS), II) water, and III) at least one compound selected from
the group consisting of formulae Xa to Xf, or a salt thereof
##STR00074## ##STR00075##
2. A process for the preparation of a conductive layer, comprising
the process steps: (P1) superimposing a substrate with the
composition according to claim 1; and (P2) at least partially
removing the solvent.
3. A conductive layer comprising a composition according to claim
1.
4. An electronic component comprising a conducting layer obtained
by the process according to claim 2.
5. The electronic component according to claim 4, wherein the
electronic component is an OLED, a display, an organic solar cell,
a hybrid solar cell, a field effect transistor, or a thermoelectric
generator.
6. An organic solar cell comprising a hole-injection layer, wherein
an additive in the hole-injection layer comprises a composition
according to claim 1.
7. An OLED comprising a hole-injection layer, wherein an additive
in the hole-injection layer comprises a composition according to
claim 1.
8. An electronic component comprising a conductive layer according
to claim 3.
9. A process for the preparation of a conductive layer, comprising
the process steps: (P1) superimposing a substrate with a
composition comprising water and a compound selected from the group
consisting of formulae Xa to Xf, or a salt thereof (P2) at least
partially removing the water; (P3) superimposing the substrate with
a composition according to claim 1, or with a composition
comprising a water and a conductive polymer, wherein the conductive
polymer comprises a complex of poly(3,4-ethylenedioxythiophene)
(PEDOT) and polystyrenesulfonic acid (PSS); and (P4) at least
partially removing the water.
10. A process for the preparation of a conductive layer, comprising
the process steps: (P1) superimposing a substrate with a
composition comprising a water and a conductive polymer, wherein
the conductive polymer comprises a complex of
poly(3,4-ethylenedioxythiophene) (PEDOT) and polystyrenesulfonic
acid (PSS), (P2) at least partially removing the water; (P3)
superimposing the substrate with the composition according to claim
1, or with a composition comprising water and a compound selected
from the group consisting of formulae Xa to Xf, or a salt thereof
##STR00076## ##STR00077## and (P4) at least partially removing the
water.
Description
This application is a national stage of International Patent
Application No. PCT/EP2015/076868, filed Nov. 17, 2015, which
claims the benefit of European Patent Application 14193716.9, filed
Nov. 18, 2014.
The present invention relates to a compound, to a composition
comprising this compound, to a process for the preparation of a
conductive layer using this composition, to a conductive layer
comprising the compound according to the present invention, to
electronic components comprising this conductive layer and to the
use of the compound according to the present invention as an
additive in a hole injection layer of an OLED.
Electrically conducting polymers have been used in a variety of
organic electronic devices, including in the development of
electroluminescent (EL) devices for use in light emissive displays.
With respect to EL devices, such as organic light emitting diodes
(OLEDs) containing conducting polymers, such devices generally have
the following configuration: anode/hole injection layer/EL
polymer/cathode
The anode is typically any material that has the ability to inject
holes into the otherwise filled .pi.-band of the semiconducting, EL
polymer, such as, for example, indium/tin oxide (ITO). The anode is
optionally supported on a glass or plastic substrate. The EL
polymer is typically a conjugated semiconducting polymer such as
poly(paraphenylenevinylene) or polyfluorene. The cathode is
typically any material (such as, e.g., Ca or Ba) that has the
ability to inject electrons into the otherwise empty .pi.*-band of
the semiconducting, EL polymer.
The hole injection layer (also referred to as "buffer layer") is
typically a conducting polymer and facilitates the injection of
holes from the anode into the EL polymer layer. Typical conducting
polymers employed as hole injection layer include polyaniline and
polydioxythiophenes. A well known conductive polymer that is used
to prepare conductive layers in organic electronic devices is a
complex of poly(3,4-ethylenedioxythiophene) and polystyrene
sulfonic acid, also referred to as "PEDOT/PSS". However, an OLED
the hole injection layer which is based on PEDOT/PSS is usually
characterized by an unsatisfying performance, in particular by a
comparatively short life time and a low efficiency and
luminescence.
In order to improve the performance of an OLED the hole injection
layer which is based on PEDOT/PSS the prior art suggest to add
certain additives to the PEDOT/PSS-dispersions used to form the
hole injection layer.
US 2005/0209388 A1, for example, suggest to substitute the
polystyrene sulfonic acid by colloid-forming polymeric acids such
as NAFION.RTM., wherein according to the teaching of US
2005/0209388 A1 the compositions disclosed therein are obtained by
oxidatively polymerizing the thiophene monomers in the presence of
NAFION.RTM.. US 2004/124504 A1 suggests to improve the performance
of an OLED the hole injection layer of which is based on PEDOT/PSS
by adding a plurality of nanoparticles to the dispersions. Suitable
nanoparticles disclosed in US 2004/124504 A1 are perfluorethylene
sulfonates such as NAFION.RTM.. However, using NAFION.RTM. as an
additive in hole injection layers of an OLED has the disadvantage
that these fluorinated sulfonic acid polymers are expensive, not
soluble in water (they merely form a colloid) and that they are
insoluble in organic solvents. These disadvantages limit their
compatibility with conductive polymer dispersions especially at
higher concentration.
WO 2009/096352 A1 discloses a "charge transport varnish" comprising
specific low molecular weight fluorinated sulfonic acids and
conductive polymers such as polyanilline. This varnish may have a
beneficial effect on OLED performance (i.e. low-voltage drive and
luminescence efficiency) if applied as a thin film. The fluorinated
sulfonic acids are soluble in water and in highly polar organic
solvents such as DMF. A general applicability of these substances
has not be shown, in particularly a beneficial effect of the
described low molecular weight fluorinated sulfonic acids when used
in combination with PEDOT/PSS. Moreover, the solubility of the
fluorinated sulfonic acids disclosed in WO 2009/096352 A1 in
solvents other than water is low.
It was therefore an object of the present invention to overcome the
disadvantages of the prior art in the field of organic electronic
devices, in particular of OLEDs the hole injection layer of which
is based on conductive polymers such as PEDOT/PSS.
In particular, it was an object of the present invention to provide
a low molecular weight additive with a tailored solubility in water
or organic solvents that, when used in combination with conductive
polymers such as PEDOT/PSS for the preparation of conductive layers
in organic electronic devices, in particular for the preparation of
a hole injection layer in an OLED, helps to improve the performance
of these electronic devices. In contrast to complex polymers such
as NAFION.RTM. the low-molecular weight additives should by
obtainable by a simple 1-2 step synthesis from commercially
available precursors.
A contribution to the solution of at least one of the above objects
is provided by the subject matter of the category-forming
independent claims, wherein the therefrom dependent subclaims
represent preferred embodiments of the present invention, whose
subject matter likewise make a contribution to solving at least one
object.
EMBODIMENTS
I. A compound having a general formula selected from the group
consisting of formula Ia and Ib
##STR00002## wherein K represents an aromatic or heteroaromatic
group in which in which at least one hydrogen atom may be
substituted by a functional groups selected from the group
consisting of a sulfonic acid group, a sulfuric acid group, an
ammonium group and an aliphatic group; X is selected from the group
consisting of a C--C bond, O, S, SO.sub.2 and NR', wherein R'
represents a hydrogen or an aliphatic or aromatic group; A
represents a fluorinated or perfluorinated aromatic group; n
represents an integer in the range from 2 to 6; m represents an
integer in the range from 1 to 3. II. The compound according to
embodiment I, wherein the functional group is selected from the
group consisting of i) --SO.sub.3M, wherein M is selected from the
group consisting of H.sup.+, Na.sup.+, K.sup.+, Li.sup.+,
NH.sub.4.sup.+, Ca.sup.2+ and Mg.sup.2+, ii) --OSO.sub.3M, wherein
M is selected from the group consisting of H.sup.+, Na.sup.+,
K.sup.+, Li.sup.+, NH.sub.4.sup.+, Ca.sup.2+ and Mg.sup.2+, iii)
--CO.sub.2M, wherein M is selected from the group consisting of
H.sup.+, Na.sup.+, K.sup.+, Li.sup.+, NH.sub.4.sup.+, Ca.sup.2+ and
Mg.sup.2+, iv) an ammonium group selected from the group consisting
of --N(CH.sub.3).sub.4.sup.+, --N(CH.sub.2CH.sub.3).sub.4.sup.+,
--N(C.sub.3H.sub.7).sub.4.sup.+, --N(C.sub.4H.sub.9).sub.4.sup.+,
and --N(C.sub.5H.sub.11).sub.4.sup.+, and v) an alkyl group
selected from the group consisting of --CH.sub.3, --C.sub.2H.sub.5,
--C.sub.3H.sub.7, --C.sub.4H.sub.9, --C.sub.5H.sub.11,
--C.sub.6H.sub.13, --C.sub.7H.sub.15, --C.sub.8H.sub.17,
--C.sub.9H.sub.19, --C.sub.10H.sub.21, --C.sub.11H.sub.23 and
--C.sub.12H.sub.25. III. The compound according to embodiment I or
II, wherein R' is selected from the group consisting of --CH.sub.3,
--C.sub.2H.sub.5, --C.sub.3H.sub.7 and --C.sub.4H.sub.9. IV. The
compound according to anyone of embodiments I to III, wherein K
represents a monocyclic aromatic or heteroaromatic group and
wherein the structural subunit Ia' of formula Ia or the structural
subunit Ib' of formula Ib
##STR00003## have a general structure selected from the group
consisting of general formulae IIa to IIk (for a monocyclic
aromatic group K) or from the group consisting of general formula
IIl to IIx (for a monocyclic heteroaromatic group K):
##STR00004## ##STR00005## ##STR00006## ##STR00007## wherein Y
represents S, O or NR'', wherein R'' represents a hydrogen atom or
an aliphatic group with 1 to 20 carbon atoms, R is selected from
the group consisting of H, --SO.sub.3M, --OSO.sub.3M, --CO.sub.2M,
--N(CH.sub.3).sub.4.sup.+, --N(CH.sub.2CH.sub.3).sub.4.sup.+,
--N(C.sub.3H.sub.7).sub.4.sup.+, --N(C.sub.4H.sub.9).sub.4.sup.+,
--N(C.sub.5H.sub.11).sub.4.sup.+, --CH.sub.3, --C.sub.2H.sub.5,
--C.sub.3H.sub.7, --C.sub.4H.sub.9, --C.sub.5H.sub.11,
--C.sub.6H.sub.13, --C.sub.7H.sub.15, --C.sub.8H.sub.17,
--C.sub.9H.sub.19, --C.sub.10H.sub.21, --C.sub.11H.sub.23, and
--C.sub.12H.sub.25, wherein M is as defined in embodiment II and
wherein the dotted line indicates the bond to A. V. The compound
according to embodiment IV, wherein X represents O and wherein the
following combinations for substituent R per entity K are
fulfilled: n=2, and R=1.times.--SO.sub.3M and 3.times.H or
R=2.times.--SO.sub.3M and 2.times.H, or n=3, and R=3.times.H or
R=3.times.--SO.sub.3M, wherein M is as defined in embodiment II.
VI. The compound according to anyone of embodiments I to III,
wherein K represents a bicyclic aromatic or heteroaromatic group, n
represents 2 and wherein the structural subunit Ia' of formula Ia
or the structural subunit Ib' of formula Ib
##STR00008## have a general structure selected from the group
consisting of general formulae IIIa to IIIj (for a bicyclic
aromatic group K) or from the group consisting of general formula
IIIk to IIIu (for a bicyclic heteroaromatic group K):
##STR00009## ##STR00010## ##STR00011## ##STR00012## wherein Y
represents S, O or NR'', wherein R'' represents a hydrogen atom or
an aliphatic group with 1 to 20 carbon atoms, R is selected from
the group consisting of H, --SO.sub.3M, --OSO.sub.3M, --CO.sub.2M,
--N(CH.sub.3).sub.4.sup.+, --N(CH.sub.2CH.sub.3).sub.4.sup.+,
--N(C.sub.3H.sub.7).sub.4.sup.30, --N(C.sub.4H.sub.9).sub.4.sup.+,
--N(C.sub.5H.sub.11).sub.4.sup.+, --CH.sub.3, --C.sub.2H.sub.5,
--C.sub.3H.sub.7, --C.sub.4H.sub.9, --C.sub.5H.sub.11,
--C.sub.6H.sub.13, --C.sub.7H.sub.15, --C.sub.8H.sub.17,
--C.sub.9H.sub.19, --C.sub.10H.sub.21, --C.sub.11H.sub.23, and
--C.sub.12H.sub.25, wherein M is as defined in embodiment II and
wherein the dotted line indicates the bond to A. VII. The compound
according to embodiment VI, wherein X represents O and wherein the
following combinations for substituent R per entity K are
fulfilled: R=2.times.--SO.sub.3M and 4.times.H, or
R=3.times.--SO.sub.3M and 3.times.H, wherein M is as defined in
embodiment II. VIII. The compound according to anyone of
embodiments I to III, wherein K represents a bicyclic aromatic or
heteroaromatic group, n represents 3 and wherein the structural
subunit Ia' of formula Ia or the structural subunit Ib' of formula
Ib
##STR00013## have a general structure selected from the group
consisting of general formulae IVa to IVl (for a bicyclic aromatic
group K) or from the group consisting of general formula IVm and
IVn (for a bicyclic heteroaromatic group K):
##STR00014## ##STR00015## ##STR00016## wherein R is selected from
the group consisting of H, --SO.sub.3M, --OSO.sub.3M, --CO.sub.2M,
--N(CH.sub.3).sub.4.sup.+, --N(CH.sub.2CH.sub.3).sub.4.sup.+,
--N(C.sub.3H.sub.7).sub.4.sup.+, --N(C.sub.4H.sub.9).sub.4.sup.-,
--N(C.sub.5H.sub.11).sub.4.sup.+, --CH.sub.3, --C.sub.2H.sub.5,
--C.sub.3H.sub.7, --C.sub.4H.sub.9, --C.sub.5H.sub.11,
--C.sub.6H.sub.13, --C.sub.7H.sub.15, --C.sub.8H.sub.17,
--C.sub.9H.sub.19, --C.sub.10H.sub.21, --C.sub.11H.sub.23, and
--C.sub.12H.sub.25, wherein M is as defined in embodiment II and
wherein the dotted line indicates the bond to A. IX. The compound
according to anyone of embodiments I to III, wherein K represents a
bicyclic aromatic or heteroaromatic group, n represents 4 and
wherein the structural subunit Ia' of formula Ia or the structural
subunit Ib' of formula Ib
##STR00017## have a general structure selected from the group
consisting of general formulae Va to Vi:
##STR00018## ##STR00019## wherein R is selected from the group
consisting of H, --SO.sub.3M, --OSO.sub.3M, --CO.sub.2M,
--N(CH.sub.3).sub.4.sup.+, --N(CH.sub.2CH.sub.3).sub.4.sup.+,
--N(C.sub.3H.sub.7).sub.4.sup.+, --N(C.sub.4H.sub.9).sub.4.sup.-,
--N(C.sub.5H.sub.11).sub.4.sup.+, --CH.sub.3, --C.sub.2H.sub.5,
--C.sub.3H.sub.7, --C.sub.4H.sub.9, --C.sub.5H.sub.11,
--C.sub.6H.sub.13, --C.sub.7H.sub.15, --C.sub.8H.sub.17,
--C.sub.9H.sub.19, --C.sub.10H.sub.21, --C.sub.11H.sub.23, and
--C.sub.12H.sub.25, wherein M is as defined in embodiment II and
wherein the dotted line indicates the bond to A. X. The compound
according to anyone of embodiments I to III, wherein K represents a
bicyclic aromatic or heteroaromatic group, n represents 5 and
wherein the structural subunit Ia' of formula Ia or the structural
subunit Ib' of formula Ib
##STR00020## have a general structure selected from the group
consisting of general formulae VIa to VIe:
##STR00021## wherein R is selected from the group consisting of H,
--SO.sub.3M, --OSO.sub.3M, --CO.sub.2M, --N(CH.sub.3).sub.4.sup.+,
--N(CH.sub.2CH.sub.3).sub.4.sup.+, --N(C.sub.3H.sub.7).sub.4.sup.+,
--N(C.sub.4H.sub.9).sub.4.sup.-, --N(C.sub.5H.sub.11).sub.4.sup.+,
--CH.sub.3, --C.sub.2H.sub.5, --C.sub.3H.sub.7, --C.sub.4H.sub.9,
--C.sub.5H.sub.11, --C.sub.6H.sub.13, --C.sub.7H.sub.13,
--C.sub.8H.sub.17, --C.sub.9H.sub.19, --C.sub.10H.sub.21,
--C.sub.11H.sub.23 and --C.sub.12H.sub.25, wherein M is as defined
in embodiment II and wherein the dotted line indicates the bond to
A. XI. The compound according to anyone of embodiments I to III,
wherein K represents a bicyclic aromatic or heteroaromatic group, n
represents 6 and wherein the structural subunit Ia' of formula Ia
or the structural subunit Ib' of formula Ib
##STR00022## have a general structure selected from the group
consisting of general formulae VIIa to VIIj:
##STR00023## ##STR00024## herein R is selected from the group
consisting of H, --SO.sub.3M, --OSO.sub.3M, --CO.sub.2M,
--N(CH.sub.3).sub.4.sup.+, --N(CH.sub.2CH.sub.3).sub.4.sup.+,
--N(C.sub.3H.sub.7).sub.4.sup.+, --N(C.sub.4H.sub.9).sub.4.sup.-,
--N(C.sub.5H.sub.11).sub.4.sup.+, --CH.sub.3, --C.sub.2H.sub.5,
--C.sub.3H.sub.7, --C.sub.4H.sub.9, --C.sub.5H.sub.11,
--C.sub.6H.sub.13, --C.sub.7H.sub.15, --C.sub.8H.sub.17,
--C.sub.9H.sub.19, --C.sub.10H.sub.21, --C.sub.11H.sub.23 and
--C.sub.12H.sub.25, wherein M is as defined in embodiment II and
wherein the dotted line indicates the bond to A. XII. The compound
according to anyone of embodiments I to III, wherein K represents a
tricyclic aromatic or heteroaromatic group and wherein the
structural subunit Ia' of formula Ia or the structural subunit Ib'
of formula Ib
##STR00025## have a general structure selected from the group
consisting of general formulae VIIIa to VIIIr (for a tricyclic
aromatic group K) or have the general formula VIIIs to VIIIu (for a
tricyclic heteroaromatic group K):
##STR00026## ##STR00027## ##STR00028## ##STR00029## wherein R is
selected from the group consisting of H, --SO.sub.3M, --OSO.sub.3M,
--CO.sub.2M, --N(CH.sub.3).sub.4.sup.+,
--N(CH.sub.2CH.sub.3).sub.4.sup.+, --N(C.sub.3H.sub.7).sub.4.sup.+,
--N(C.sub.4H.sub.9).sub.4.sup.-, --N(C.sub.5H.sub.11).sub.4.sup.+,
--CH.sub.3, --C.sub.2H.sub.5, --C.sub.3H.sub.7, --C.sub.4H.sub.9,
--C.sub.5H.sub.11, --C.sub.6H.sub.13, --C.sub.7H.sub.15,
--C.sub.8H.sub.17, --C.sub.9H.sub.19, --C.sub.10H.sub.21,
--C.sub.11H.sub.23 and --C.sub.12H.sub.25, wherein M is as defined
in embodiment II and wherein the dotted line indicates the bond to
A. XIII. The compound according to anyone of embodiments I to XII,
wherein A has a general structure selected from the group
consisting of general formulae IXa to IXo:
##STR00030## ##STR00031## ##STR00032## wherein the dotted line
indicates the bond to X. XIV. The compound according to anyone of
embodiments I to XIII, wherein the compound has a general structure
selected from the group consisting of general formulae Xa to Xg or
the corresponding salts thereof:
##STR00033## ##STR00034## ##STR00035## XV. A composition comprising
I) at least one conductive polymer, II) at least one solvent and
III) at least one compound according to anyone of embodiments I to
XIV. XVI. The composition according to embodiment XV, wherein the
conductive polymer I) comprises a polythiophene. XVII. The
composition according to anyone of embodiments XV and XVI, wherein
the solvent II) is water, an organic solvent selected from the
group consisting of alcohols, aliphatic hydrocarbons, aromatic
hydrocarbons, ethers, halogenated hydrocarbons, aliphatic nitriles,
aliphatic carboxylic acids, aliphatic carboxylic acid and ketones
or a mixture of at least two of these solvents. XVIII. A process
for the preparation of a conductive layer, comprises the process
steps: (P1) superimposing a substrate with the composition
according to anyone of embodiment XV to XVII; or first
superimposing a substrate with a composition comprising the solvent
and the compound according to anyone of embodiments I to XIV, at
least partial removal of the solvent and then superimposing the
substrate with a composition according to anyone of embodiments XV
to XVII or with a composition comprising the solvent and the
conductive polymer; or first superimposing a substrate with a
composition comprising the solvent and the conductive polymer, at
least partial removal of the solvent and then superimposing the
substrate with the composition according to anyone of embodiments
XV to XVII or with a composition comprising the solvent the
compound according to anyone of embodiments I to XIV; (P2) at least
partial removal of the solvent. XIX. A conductive layer comprising
at least one compound according to anyone of embodiments I to XIV.
XX. An electronic component comprising a conducting layer
obtainable by the process according to embodiment XVIII or
comprising a conductive layer according to embodiments XIX. XXI.
The electronic component according to embodiments XX, wherein the
electronic component is an OLED, a display, an organic solar cell,
a hybrid solar cell, a field effect transistor, or a thermoelectric
generator. XXII. Use of at least one compound according to anyone
of embodiments I to XIV as an additive in a hole-injection layer of
an OLED or in an organic solar cell.
A contribution towards solving these objects is made by a compound
having a general formula selected from the group consisting of
formula Ia and Ib
##STR00036##
wherein K represents an aromatic or heteroaromatic group,
preferably a mono-, di- or tricyclic aromatic or heteroaromatic
group, in which at least one hydrogen atom may be substituted by a
functional group selected from the group consisting of a sulfonic
acid group, a sulfuric acid group, an ammonium group and an
aliphatic group; X is selected from the group consisting of a C--C
bond, O, S, SO.sub.2 and NR', preferably selected from the group
consisting of O, S, SO.sub.2 and NR', wherein R' represents a
hydrogen or an aliphatic or aromatic group, preferably an alkyl
group and most preferably an alkyl group selected from the group
consisting of --CH.sub.3, --C.sub.2H.sub.5, --C.sub.3H.sub.7 and
--C.sub.4H.sub.9, wherein it is most preferred that X represents O;
A represents a fluorinated or perfluorinated aromatic group; n
represents an integer in the range from 2 to 6, preferably 2 or 3;
m represents an integer in the range from 1 to 3, preferably 1.
It is preferred that in the compound according to the present
invention the functional group (i.e. the functional group with
which at least one hydrogen atom of the aromatic group K may be
substituted) is a functional groups selected from the group
consisting of i) --SO.sub.3M, wherein M is selected from the group
consisting of H.sup.+, Na.sup.+, K.sup.+, Li.sup.+, NH.sub.4.sup.+,
Ca.sub.2.sup.+ and Mg.sup.2+, ii) --OSO.sub.3M, wherein M is
selected from the group consisting of H.sup.+, Na.sup.+, K.sup.+,
Li.sup.+, NH.sub.4.sup.+, Ca.sup.2+ and Mg.sup.2+, iii)
--CO.sub.2M, wherein M is selected from the group consisting of
H.sup.+, Na.sup.+, K.sup.+, Li.sup.+, NH.sub.4.sup.+, Ca.sup.2+ and
Mg.sup.2+, iv) an ammonium group selected from the group consisting
of --N(CH.sub.3).sub.4.sup.+, --N(CH.sub.2CH.sub.3).sub.4.sup.+,
--N(C.sub.3H.sub.7).sub.4.sup.+, --N(C.sub.4H.sub.9).sub.4.sup.+,
and --N(C.sub.5H.sub.11).sub.4.sup.+, and v) an alkyl group
selected from the group consisting of --CH.sub.3, --C.sub.2H.sub.5,
--C.sub.3H.sub.7, --C.sub.4H.sub.9, --C.sub.5H.sub.11,
--C.sub.6H.sub.13, --C.sub.7H.sub.15, --C.sub.8H.sub.17,
--C.sub.9H.sub.19, --C.sub.10H.sub.21, --C.sub.11H.sub.23 and
--C.sub.12H.sub.25.
Functional groups i), ii), iii) and iv) are preferred if the
compounds according to the present invention are used in
water-based compositions, whereas functional group v) (or compounds
in which no hydrogen atoms are substituted by any of these
functional groups i) to v)) are preferred for compositions that are
based on organic solvents.
According to preferred embodiments of the compound according to the
present invention 1, 2, 3 or 4 hydrogen atoms, preferably 1 or 2
hydrogen atoms of the heteroaromatic or heteroaromatic group K are
substituted by one of the above mentioned functional groups
selected from the group consisting of a sulfonic acid group, a
sulfuric acid group, an ammonium group and an aliphatic group.
As in the compound according to the present invention two or more
hydrogen atoms of the aromatic group K may be substituted by any of
the above mentioned functional groups, these groups may be
identical or different. However, according to a particularly
preferred embodiment of the compound according to the present
invention the functional group is --SO.sub.3M, wherein M is
selected from the group consisting of H.sup.+, Na.sup.+, K.sup.+,
Li.sup.+, NH.sub.4.sup.+, Ca.sup.2+ and Mg.sup.2+, and if more than
one hydrogen atom of the aromatic group K is substituted by a
functional group, all these groups are --SO.sub.3M groups, wherein
M is selected from the group consisting of H.sup.+, Na.sup.+,
K.sup.+, Li.sup.+, NH.sub.4.sup.+, Ca.sup.2+ and Mg.sup.2+.
According to a first embodiment of the compound according to the
present invention K represents a monocyclic aromatic group or a
monocyclic heteroaromatic group and the structural subunit Ia' of
formula Ia or the structural subunit Ib' of formula Ib
##STR00037##
have a general structure selected from the group consisting of
general formulae IIa to IIk (for a monocyclic aromatic group K) or
from the group consisting of general formula III to IIx (for a
monocyclic heteroaromatic group K) (hydrogen atoms in formula IIw
and IIx are not shown):
##STR00038## ##STR00039## ##STR00040##
wherein Y represents S, O or NR'', wherein R'' represents a
hydrogen atom or an aliphatic group with 1 to 20 carbon atoms,
preferably a C.sub.1-C.sub.10 alkyl group, R is selected from the
group consisting of H, --SO.sub.3M, --OSO.sub.3M, --CO.sub.2M,
--N(CH.sub.3).sub.4.sup.+, --N(CH.sub.2CH.sub.3).sub.4.sup.+,
--N(C.sub.3H.sub.7).sub.4.sup.+, --N(C.sub.4H.sub.9).sub.4.sup.+,
--N(C.sub.5H.sub.11).sub.4.sup.+, --CH.sub.3, --C.sub.2H.sub.5,
--C.sub.3H.sub.7, --C.sub.4H.sub.9, --C.sub.5H.sub.11,
--C.sub.6H.sub.13, --C.sub.7H.sub.15, --C.sub.8H.sub.17,
--C.sub.9H.sub.19, --C.sub.10H.sub.21, --C.sub.11H.sub.23 and
--C.sub.12H.sub.25, wherein M is selected from the group consisting
of H.sup.+, Na.sup.+, K.sup.+, Li.sup.+, NH.sub.4.sup.+, Ca.sup.2+
and Mg.sup.2+,
and wherein the dotted line indicates the bond to A.
From the compounds of the first embodiment according to the present
invention particularly preferred compounds are those in which X
represents O and in which the following combinations for
substituent R per entity K are fulfilled:
n=2, and
R=1.times.--SO.sub.3M and 3.times.H or R=2.times.--SO.sub.3M and
2.times.H,
or
n=3, and
R=3.times.H and 3.times.--SO.sub.3M,
wherein M is selected from the group consisting of H.sup.+,
Na.sup.+, K.sup.+, Li.sup.+, NH.sub.4.sup.+, Ca.sup.2+ and
Mg.sup.2+.
According to a second embodiment of the compound according to the
present invention K represents a bicyclic aromatic group (i.e. K is
based on a naphthalene group) or a bicyclic heteroaromatic
group.
According to a first variant of the second embodiment of the
compound according to the present invention n represents 2 and the
structural subunit Ia' of formula Ia or the structural subunit Ib'
of formula Ib
##STR00041##
have a general structure selected from the group consisting of
general formulae IIIa to IIIj (for a bicyclic aromatic group K) or
from the group consisting of general formula IIIk to IIIu (for a
bicyclic heteroaromatic group K) (hydrogen atoms in formula IIIK to
IIIu are not shown):
##STR00042## ##STR00043## ##STR00044##
wherein Y represents S, O or NR'', wherein R'' represents a
hydrogen atom or an aliphatic group with 1 to 20 carbon atoms,
preferably a C.sub.1-C.sub.10 alkyl group, R is selected from the
group consisting of H, --SO.sub.3M, --OSO.sub.3M, --CO.sub.2M,
--N(CH.sub.3).sub.4.sup.+, --N(CH.sub.2CH.sub.3).sub.4.sup.+,
--N(C.sub.3H.sub.7).sub.4.sup.+, --N(C.sub.4H.sub.9).sub.4.sup.+,
--N(C.sub.5H.sub.11).sub.4.sup.+, --CH.sub.3, --C.sub.2H.sub.5,
--C.sub.3H.sub.7, --C.sub.4H.sub.9, --C.sub.5H.sub.11,
--C.sub.6H.sub.13, --C.sub.7H.sub.15, --C.sub.8H.sub.17,
--C.sub.9H.sub.19, --C.sub.10H.sub.21, --C.sub.11H.sub.23 and
--C.sub.12H.sub.25, wherein M is selected from the group consisting
of H.sup.+, Na.sup.+, K.sup.+, Li.sup.+, NH.sub.4.sup.+, Ca.sup.2+
and Mg.sup.2+,
and wherein the dotted line indicates the bond to A.
In context with this first variant of the second embodiment
compounds are particularly preferred in which X represents O and in
which the following combinations for substituent R per entity K are
fulfilled:
R=2.times.--SO.sub.3M and 4.times.H,
or
R=3.times.--SO.sub.3M and 3.times.H,
wherein M is selected from the group consisting of H.sup.+,
Na.sup.+, K.sup.+, Li.sup.+, NH.sub.4.sup.+, Ca.sup.2+ and
Mg.sup.2+.
According to a second variant of the second embodiment of the
compound according to the present invention n represents 3 and the
structural subunit Ia' of formula Ia or the structural subunit Ib'
of formula Ib
##STR00045##
have a general structure selected from the group consisting of
general formulae IVa to IVl (for a bicyclic aromatic group K) or
from the group consisting of general formula IVm and IVn (for a
bicyclic heteroaromatic group K) (hydrogen atoms in formula IIIm
and IIIn are not shown):
##STR00046## ##STR00047## ##STR00048##
wherein R is selected from the group consisting of H, --SO.sub.3M,
--OSO.sub.3M, --CO.sub.2M, --N(CH.sub.3).sub.4.sup.+,
--N(CH.sub.2CH.sub.3).sub.4.sup.+, --N(C.sub.3H.sub.7).sub.4.sup.+,
--N(C.sub.4H.sub.9).sub.4.sup.+, --N(C.sub.5H.sub.11).sub.4.sup.+,
--CH.sub.3, --C.sub.2H.sub.5, --C.sub.3H.sub.7, --C.sub.4H.sub.9,
--C.sub.5H.sub.11, --C.sub.6H.sub.13, --C.sub.7H.sub.15,
--C.sub.8H.sub.17, --C.sub.9H.sub.19, --C.sub.10H.sub.21,
--C.sub.11H.sub.23 and --C.sub.12H.sub.25, wherein M is selected
from the group consisting of H.sup.+, Na.sup.+, K.sup.+, Li.sup.+,
NH.sub.4.sup.+, Ca.sup.2+ and Mg.sup.2+ and wherein the dotted line
indicates the bond to A.
According to a third variant of the second embodiment of the
compound according to the present invention n represents 4 and the
structural subunit Ia' of formula Ia or the structural subunit Ib'
of formula Ib
##STR00049##
have a general structure selected from the group consisting of
general formulae Va to Vi:
##STR00050## ##STR00051##
wherein R is selected from the group consisting of H, --SO.sub.3M,
--OSO.sub.3M, --CO.sub.2M, --N(CH.sub.3).sub.4.sup.+,
--N(CH.sub.2CH.sub.3).sub.4.sup.+, --N(C.sub.3H.sub.7).sub.4.sup.+,
--N(C.sub.4H.sub.9).sub.4.sup.+, --N(C.sub.5H.sub.11).sub.4.sup.+,
--CH.sub.3, --C.sub.2H.sub.5, --C.sub.3H.sub.7, --C.sub.4H.sub.9,
--C.sub.5H.sub.11, --C.sub.6H.sub.13, --C.sub.7H.sub.15,
--C.sub.8H.sub.17, --C.sub.9H.sub.19, --C.sub.10H.sub.21,
--C.sub.11H.sub.23 and --C.sub.12H.sub.25, wherein M is selected
from the group consisting of H.sup.+, Na.sup.+, K.sup.+, Li.sup.+,
NH.sub.4.sup.+, Ca.sup.2+ and Mg.sup.2+ and wherein the dotted line
indicates the bond to A.
According to a forth variant of the second embodiment of the
compound according to the present invention n represents 5 and the
structural subunit Ia' of formula Ia or the structural subunit Ib'
of formula Ib
##STR00052##
have a general structure selected from the group consisting of
general formulae VIa to VIe:
##STR00053##
wherein R is selected from the group consisting of H, --SO.sub.3M,
--OSO.sub.3M, --CO.sub.2M, --N(CH.sub.3).sub.4.sup.+,
--N(CH.sub.2CH.sub.3).sub.4.sup.+, --N(C.sub.3H.sub.7).sub.4.sup.+,
--N(C.sub.4H.sub.9).sub.4.sup.+, --N(C.sub.5H.sub.11).sub.4.sup.+,
--CH.sub.3, --C.sub.2H.sub.5, --C.sub.3H.sub.7, --C.sub.4H.sub.9,
--C.sub.5H.sub.11, --C.sub.6H.sub.13, --C.sub.7H.sub.15,
--C.sub.8H.sub.17, --C.sub.9H.sub.19, --C.sub.10H.sub.21,
--C.sub.11H.sub.23 and --C.sub.12H.sub.25, wherein M is selected
from the group consisting of H.sup.+, Na.sup.+, K.sup.+, Li.sup.+,
NH.sub.4.sup.+, Ca.sup.2+ and Mg.sup.2+ and wherein the dotted line
indicates the bond to A.
According to a fifth variant of the second embodiment of the
compound according to the present invention n represents 6 and the
structural subunit Ia' of formula Ia or the structural subunit Ib'
of formula Ib
##STR00054##
have a general structure selected from the group consisting of
general formulae VIIa to VIIj:
##STR00055## ##STR00056##
wherein R is selected from the group consisting of H, --SO.sub.3M,
--OSO.sub.3M, --CO.sub.2M, --N(CH.sub.3).sub.4.sup.+,
--N(CH.sub.2CH.sub.3).sub.4.sup.+, --N(C.sub.3H.sub.7).sub.4.sup.+,
--N(C.sub.4H.sub.9).sub.4.sup.+, --N(C.sub.5H.sub.11).sub.4.sup.+,
--CH.sub.3, --C.sub.2H.sub.5, --C.sub.3H.sub.7, --C.sub.4H.sub.9,
--C.sub.5H.sub.11, --C.sub.6H.sub.13, --C.sub.7H.sub.15,
--C.sub.8H.sub.17, --C.sub.9H.sub.19, --C.sub.10H.sub.21,
--C.sub.11H.sub.23 and --C.sub.12H.sub.25, wherein M is selected
from the group consisting of H.sup.+, Na.sup.+, K.sup.+, Li.sup.+,
NH.sub.4.sup.+, Ca.sup.2+ and Mg.sup.2+ and wherein the dotted line
indicates the bond to A.
According to a third embodiment of the compound according to the
present invention K represents a tricyclic aromatic group (i.e. K
is based on a anthracene group or a phenanthrene group) or a
tricyclic heteroaromatic group and the structural subunit Ia' of
formula Ia or the structural subunit Ib' of formula Ib
##STR00057##
have a general structure selected from the group consisting of
general formulae VIIIa to VIIIr (for a tricyclic aromatic group K)
or have the general formula VIIIs to VIIIu (for a tricyclic
heteroaromatic group K) (hydrogen atoms in formula VIIIs, VIIIt and
VIIIu are not shown):
##STR00058## ##STR00059## ##STR00060## ##STR00061##
wherein Y represents S, O or NR'', wherein R'' represents a
hydrogen atom or an aliphatic group with 1 to 20 carbon atoms,
preferably a C.sub.1-C.sub.10 alkyl group, R is selected from the
group consisting of H, --SO.sub.3M, --OSO.sub.3M, --CO.sub.2M,
--N(CH.sub.3).sub.4.sup.+, --N(CH.sub.2CH.sub.3).sub.4.sup.+,
--N(C.sub.3H.sub.7).sub.4.sup.+, --N(C.sub.4H.sub.9).sub.4.sup.+,
--N(C.sub.5H.sub.11).sub.4.sup.+, --CH.sub.3, --C.sub.2H.sub.5,
--C.sub.3H.sub.7, --C.sub.4H.sub.9, --C.sub.5H.sub.11,
--C.sub.7H.sub.15, --C.sub.8H.sub.17, --C.sub.9H.sub.19,
--C.sub.10H.sub.21, --C.sub.11H.sub.23 and --C.sub.12H.sub.25,
wherein M is selected from the group consisting of H.sup.+,
Na.sup.+, K.sup.+, Li.sup.+, NH.sub.4.sup.+, Ca.sup.2+ and
Mg.sup.2+,
and wherein the dotted line indicates the bond to A.
In context with the third embodiment compounds are particularly
preferred in which X represents O and in which the following
combinations for substituent R per entity K are fulfilled:
R=2.times.--SO.sub.3M and 6.times.H,
or
R=3.times.--SO.sub.3M and 5.times.H,
wherein M is selected from the group consisting of H.sup.+,
Na.sup.+, K.sup.+, Li.sup.+, NH.sub.4.sup.+, Ca.sup.2+ and
Mg.sup.2+
In the compound according to the present invention A represents a
fluorinated or perfluorinated aromatic group, more preferably a
perfluorinated aromatic group. In this context it is particularly
preferred that A has a general structure selected from the group
consisting of general formulae IXa to IXo:
##STR00062## ##STR00063## ##STR00064##
wherein the dotted line indicates the bond to X.
Particularly preferred embodiments of the compound according to the
present invention have a general structure selected from the group
consisting of general formulae Xa to Xg or the corresponding salts
thereof:
##STR00065## ##STR00066##
It should be noted that, although in general formulae Xa to Xg the
functional groups are shown to be --SO.sub.3H groups, these groups
can of course also be partially or completely neutralized and can
therefore also be present in the form of --SO.sub.3M groups, in
which M is selected from the group consisting of H.sup.+, Na.sup.+,
K.sup.+, Li.sup.+, NH.sub.4.sup.+, Ca.sup.2+ and Mg.sup.2+.
The compound according to the present invention can be prepared in
a simply one-step synthesis by reacting the mono- or polycyclic
aromatic or heteroaromatic system K in which at least one hydrogen
atom may be substituted by the above mentioned functional groups
and in which at the position at which X is attached the
corresponding acid form --XH is present, i.e. a group --OH in case
of X.dbd.O, a group --SH in case of X.dbd.S, a group --SO.sub.2H in
case of X.dbd.SO.sub.2, or a group --NR'H in case of X.dbd.NR',
with a fluorinated or perfluorinated aromatic compound, preferably
with a perfluorinated aromatic compound having a general structure
selected from the group consisting of general formulae XIa to
XIh:
##STR00067## ##STR00068##
in a nucleophilic aromatic substitution reaction, preferably in the
presence of a suitable catalyst. Catalysts that can be used for
this purpose can be selected from the group consisting of lithium,
potassium, lithium hydride, sodium hydride, lithium t-butoxide,
sodium t-butoxide, potassium t-butoxide, lithium-diisopropylamide,
n-butyllithium, s-butyllithium, t-butyllithium, lithium
hexamethyldisilazide, sodium hexamethyldisilazide, potassium
hexamethyldisilazide, lithium hydroxide, sodium hydroxide,
potassium hydroxide, barium hydroxide, barium oxide, lithium
carbonate, sodium carbonate, potassium carbonate, cesium carbonate,
calcium carbonate, sodium hydrogen carbonate, triethylamine,
diisopropylethylamine, tetramethylethylenediamine,
triethylenediamine, pyridine, dimethylaminopyridine, imidazole and
the like, and dehydration condensing agents such as hydrochloric
acid, sulfuric acid, diphosphorus pentaoxide, aluminum (III)
chloride, boron trifluoride diethyl ether complex, ethyl aluminum
dichloride, diethyl aluminum chloride and the like. Preferred
catalysts are selected from the group consisting of sodium
hydroxide, sodium carbonate and potassium carbonate.
The reaction can be performed in any solvent in which the educts
(i.e. the mono- or polycyclic aromatic or heteroaromatic system K
in which at the position at which X is attached the corresponding
acid form --XH is used and the fluorinated or perfluorinated
aromatic compound) can be dissolved or dispersed. Preferably an
aprotic polar organic solvent is used, which is preferably selected
from the group consisting N,N-dimethylformamide,
N,N-dimethyacetamide, N-methylpyrrolidone,
1,3-dimethyl-2-imidazolidinone, dimethylsulfoxide, tetrahydrofuran
and dioxane.
The possible reaction temperature generally ranges from 50.degree.
C. to the boiling point of a solvent used and is preferably within
a range of 0 to 140.degree. C. The reaction time is usually at 0.1
to 100 hours. After completion of the reaction, purification can be
made by distilling off of the reaction solvent, protonation of the
sulfonate by means of a cationic exchange resins, extraction
operations with a solvent such as methanol or the like, or by
precipitation.
A contribution towards solving the above mentioned objects is also
made by a composition comprising
I) at least one conductive polymer,
II) at least one solvent and
III) at least one compound according to the present invention,
wherein the composition preferably is a dispersion or a solution,
particularly preferred dispersion.
Conductive polymers I) are understood here to mean especially the
compound class of the conjugated polymers which, after oxidation or
reduction, possess electrical conductivity. Preferably, such
conjugated polymers are considered to be conductive polymers which,
after oxidation, possess an electrical conductivity in the order of
magnitude of at least 0.01 .mu.S cm.sup.-1.
The conductive polymer I) in the composition according to the
present invention preferably comprises, as a conjugated polymer, at
least one polythiophene, polypyrrole or polyaniline, which are
optionally substituted.
More preferably, the conductive polymer I) comprises at least one
polythiophene with repeat units of the general formula (A) or of
the general formula (B) or a combination of units of the general
formulas (A) and (B), preferably a polythiophene with repeating
units of the general formula (B):
##STR00069##
wherein z stands for an optionally substituted
C.sub.1-C.sub.5-alkylene radical, R stands for a linear or
branched, optionally substituted C.sub.1-C.sub.18-alkyl radical, an
optionally substituted C.sub.5-C.sub.12-cycloalkyl radical, an
optionally substituted C.sub.6-C.sub.14-aryl radical, an optionally
substituted C.sub.7-C.sub.18-aralkyl radical, an optionally
substituted C.sub.1-C.sub.4-hydroxyalkyl radical or a hydroxyl
radical, x stands for a whole number from 0 to 8 and
in the case where multiple radicals R are connected to Y, these can
be identical or different.
The general formulas (A) and (B) are to be so understood, that x
substituents R can be connected to alkylene radical Y.
Particularly preferred are polythiophenes with repeating units of
the general formula (B), wherein z stands for an optionally
substituted C.sub.2-C.sub.3-alkylene radical and x stands for 0 or
1. Especially preferred as polythiophene is
poly(3,4-ethylenedioxythiophene), which is optionally
substituted.
In the context of the invention, the prefix poly- is to be
understood as meaning that more than one identical or different
repeating units of the general formulas (A) and/or (B) are
contained in the polymer or polythiophene. As well as the repeating
units of the general formulas (A) and/or (B), the polythiophene can
also comprise other repeating units, it being preferred that at
least 50%, particularly preferred that at least 75% and most
preferred that at least 95% of all repeating units of the
polythiophene exhibit the general formula(s) (A) and/or (B),
preferably the general formula (B). The polythiophenes contain in
total n repeating units of the general formula(s) (A) and/or (B),
preferably of the general formula (B), n being a whole number from
2 to 2000, preferably from 2 to 100. The repeating units of the
general formula(s) (A) and/or (B), preferably of the general
formula (B), within a polythiophene can each be identical or
different. Polythiophenes with identical repeating units of the
general formula (B) are preferred.
The polythiophenes preferably carry H on the end groups.
In the context of the invention, C.sub.1-C.sub.5-alkylene radicals
z are preferably methylene, ethylene, n-propylene, n-butylene or
n-pentylene. C.sub.1-C.sub.18-Alkyl R is preferably linear or
branched C.sub.1-C.sub.18-alkyl radicals such as methyl, ethyl, n-
or isopropyl, n-, iso-, sec- or tert-butyl, n-pentyl,
1-methylbutyl, 2-methylbutyl, 3-methylbutyl, 1-ethylpropyl,
1,1-dimethylpropyl, 1,2-dimethylpropyl, 2,2-dimethylpropyl,
n-hexyl, n-heptyl, n-octyl, 2-ethylhexyl, n-nonyl, n-decyl,
n-undecyl, n-dodecyl, n-tridecyl, n-tetradecyl, n-hexadecyl or
n-octadecyl, C.sub.5-C.sub.12-cycloalkyl radicals R are, for
example, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl,
cyclononyl or cyclodecyl, C.sub.6-C.sub.14-aryl radicals R are, for
example, phenyl or naphthyl, and C.sub.7-C.sub.18-aralkyl radicals
R are, for example, benzyl, o-, m-, p-tolyl, 2,3-, 2,4-, 2,5-,
2,6-, 3,4-, 3,5-xylyl or mesityl. The above list serves to
illustrate the invention by way of example and should not be
considered to be exclusive.
In the context of the invention, any further substituents of the z
radicals and/or of the R radicals include numerous organic groups,
for example alkyl, cycloalkyl, aryl, aralkyl, alkoxy, halogen,
ether, thioether, disulfide, sulfoxide, sulfone, sulfonate, amino,
aldehyde, keto, carboxylic ester, carboxylic acid, carbonate,
carboxylate, cyano, alkylsilane and alkoxysilane groups, and also
carboxamide groups.
Possible substituents for polyaniline or polypyrrole include, for
example, the z and R radicals listed above and/or the further
substituents of the z and R radicals. Preference is given to
unsubstituted polyanilines.
The polythiophenes that are comprised in the conductive polymer I)
may be uncharged or cationic. In preferred embodiments, they are
cationic, "cationic" relating only to the charges which reside on
the main polythiophene chain. According to the substituent on the R
radicals, the polythiophenes may bear positive and negative charges
in the structural unit, in which case the positive charges are on
the main polythiophene chain and the negative charges are, if
present, on the R radicals substituted by sulfonate or carboxylate
groups. The positive charges of the main polythiophene chain may be
partly or fully saturated by the anionic groups which may be
present on the R radicals. Viewed overall, the polythiophenes in
these cases may be cationic, uncharged or even anionic.
Nevertheless, in the context of the invention, all are considered
to be cationic polythiophenes, since the positive charges on the
main polythiophene chain are crucial. The positive charges are not
shown in the formulae, since their exact number and position cannot
be stated unambiguously. The number of positive charges is,
however, at least 1 and at most n, where n is the total number of
all repeat units (identical or different) within the
polythiophene.
To balance the positive charge, if this has not already been done
by the optionally sulfonate- or carboxylate-substituted and thus
negatively charged R radicals, the cationic polythiophenes require
anions as counterions. Counterions may be monomeric or polymeric
anions, the latter also being referred to hereinafter as
polyanions.
Polymeric anions are preferred over monomeric anions, since they
contribute to film formation and, owing to their size, lead to
thermally more stable, electrically conductive films. Polymeric
anions here may, for example, be anions of polymeric carboxylic
acids, such as polyacrylic acids, polymethacrylic acid or
polymaleic acids, or polymeric sulfonic acids, such as
polystyrenesulfonic acids and polyvinylsulfonic acids. These
polycarboxylic and -sulfonic acids may also be copolymers of
vinylcarboxylic and vinylsulfonic acids with other polymerizable
monomers, such as acrylic esters and styrene. Other preferred
copolymers are block-copolymers of polystyrenesulfonic acid,
polyalkylstyrenes and (hydrogenated) isoprenes/dienes.
A preferred polyanion is an anion of a polymeric carboxylic or
sulfonic acid. A particularly preferred polyanion is the anion of
polystyrenesulfonic acid (PSS). The molecular weight of the
polyacids which afford the polyanions is preferably 1000 to 2 000
000, more preferably 2000 to 500 000. The polyacids or alkali metal
salts thereof are commercially available, for example
polystyrenesulfonic acids and polyacrylic acids, or else are
preparable by known processes (see, for example, Houben Weyl,
Methoden der organischen Chemie [Methods of Organic Chemistry],
vol. E 20 Makromolekulare Stoffe [Macromolecular Substances], part
2, (1987), p. 1141 ff.).
Polyanions and conjugated polymer (i.e. polythiophene, polypyrrole
or polyaniline, which are optionally substituted) may be present in
the composition according to the present invention especially in a
weight ratio of 0.5:1 to 50:1, preferably of 1:1 to 30:1, more
preferably 2:1 to 20:1. The weight of the conjugated polymer
corresponds here to the initial weight of the monomers used,
assuming that there is full conversion in the polymerization.
The monomeric anions used are, for example, those of
C.sub.1-C.sub.20-alkanesulfonic acids, such as those of
methanesulfonic acid, ethanesulfonic acid, propanesulfonic acid,
butanesulfonic acid or higher sulfonic acids such as
dodecanesulfonic acid, of aliphatic perfluorosulfonic acids, such
as trifluoromethanesulfonic acid, perfluorobutanesulfonic acid or
perfluorooctanesulfonic acid, of aliphatic
C.sub.1-C.sub.20-carboxylic acids such as 2-ethylhexylcarboxylic
acid, of aliphatic perfluorocarboxylic acids, such as
trifluoroacetic acid or perfluorooctanoic acid, and aromatic
sulfonic acids optionally substituted by C.sub.1-C.sub.20-alkyl
groups, such as benzenesulfonic acid, o-toluenesulfonic acid,
p-toluenesulfonic acid or dodecylbenzenesulfonic acid, and of
cycloalkanesulfonic acids such as camphorsulfonic acid, or
tetrafluoroborates, hexafluorophosphates, perchlorates,
hexafluoroantimonates, hexafluoroarsenates or
hexachloroantimonates. Preferred monomeric anions are the anions of
p-toluenesulfonic acid, methanesulfonic acid or camphorsulfonic
acid.
Cationic polythiophenes which contain anions as counterions to
balance the charge are often also referred to in the technical
field as polythiophene/(poly)anion complexes. It is therefore
particularly preferred that in the composition according to the
present invention the conductive polymer I) comprises a complex of
a polythiophene and mono- or a polyanion or a combination of both,
preferably a complex of poly(3,4-ethylenedioxythiophene) (PEDOT)
and polystyrenesulfonic acid (PSS), also referred to as a
"PEDOT/PSS"-complex. Such complexes can be obtained if the monomers
used to prepare the polythiophene (like 3,4-ethylenedioxythiophene)
are oxidatively polymerized in the presence of the polyanions in
suitable solvents like water, as disclosed, for example, in EP 0
440 957 A2. The complexes of polythiophenes and polyanions, in
particular the PEDOT/PSS-complexes, are preferably present in the
composition according to the present invention in the form of
particles.
As a further component the composition according to the present
invention also comprises at least one solvent II).
Preferred solvents are water, organic solvents selected from the
group consisting of aliphatic hydrocarbons, such as heptane,
hexane, pentane, octane, terpenes or petroleum ether, aromatic
hydrocarbons such as benzene, toluene, xylene, mesitylene,
biphenyl, ethers, such as diethylether, diisopropylether,
methyltertbutylether dibutylether, diphenylether, anisole and
ethylenglycol ethers such as polyethylenglycol (PEG), ethylene
glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene
glycol monobutyl ether, ethylene glycol monophenyl ether,
diethylene glycol monomethyl ether, diethylene glycol monoethyl
ether, ethylene glycol dimethyl ether, ethylene glycol diethyl
ether, propylen glycol monopropyl ether, dipropylen glycol
monomethylether, dipropylen glycol dimethylether, diethylene glycol
monomethyl ether or ethylene glycol dibutyl ether, esters such as
methylacetate, ethylacetate, propylacetate or butylacetate,
methylbenzoate, ethylbenzoate, propylbenzoate, butylbenzoate,
.gamma.-butyrolactone, .delta.-valerolactone,
.gamma.-valerolactone, ethylene glycol methyl ether acetate,
ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl
ether acetate, propylene glycol methyl ether acetate, halogenated
hydrocarbons such as dichloromethane, dichloroethane,
chlorobenzene, chloroform, tetrachloromethane, trichloroethane or
trichloroethene, aliphatic nitriles such as acetonitrile, aliphatic
sulphoxides and sulphones such as dimethylsulfoxide or sulfolane,
aliphatic carboxylic acids such as acetic acid, aliphatic
carboxylic acid amides such as acetamide, dimethyl acetamide or
dimethylformamide and ketones such as acetone or methyl-t-butyl
ketone, alcohols such as methanol, ethanol, propanol, butanol,
hexanol, terpineol, 1,2-propandiol, ethylenglycol or dodecanol,
acetals such as glyme (dimethoxyethane), diglyme, tetraglyme, or
dioxolane, carbonates such as propylene carbonate or ethylene
carbonate and other solvent classes like oligo- or polysiloxanes,
and mixtures of at least two of these solvents.
As component III) the composition according to the present
invention comprises at least one compound according to the present
invention, wherein it is preferred that the composition according
to the present invention comprises the at least one compound III)
in an amount of 0.01 to 10 wt.-%, preferably 0.1 to 7.5 wt.-% and
most preferably 0.5 to 5 wt.-%, in each case based on the total
weight of the composition. The weight ratio of the at least one
compound III) and the conductive polymer I) (in case of a
polythiophene/(poly)anion complex the weight ratio of the at least
one compound III) and the total weight of polythiophene and
polyanion) is preferably in the range from 1:100 to 100:1, more
preferably in the range from 1:10 to 10:1 and most preferably in
the range from 1:5 to 5:1.
Besides at least one conductive polymer I), at least one solvent
II) and at least one compound according to the present invention
III) the composition according to the present invention may
comprise further additives IV) being different from components I),
II) and III), such as surface-active substances, e.g. anionic
surfactants, such as e.g. alkylbenzenesulphonic acids and salts,
paraffinsulphonates, alcohol sulphonates, ether sulphonates,
sulphosuccinates, phosphate esters, alkyl ether carboxylic acids or
carboxylates, cationic surfactants, such as e.g. quaternary
alkylammonium salts, nonionic surfactants, such as e.g. linear
alcohol ethoxylates, oxo alcohol ethoxylates, alkylphenol
ethoxylates or alkyl polyglucosides, adhesion promoters, such as
e.g. organofunctional silanes or hydrolysates thereof, e.g.
3-glycidoxypropyltrialkoxysilane, 3-aminopropyltriethoxysilane,
3-mercaptopropyltrimethoxysilane,
3-methacryloxypropyltrimethoxysilane, vinyltrimethoxysilane or
octyltriethoxysilane, or crosslinking agents, such as melamine
compounds, masked isocyanates, functional silanes--e.g.
tetraethoxysilane, alkoxysilane hydrolysates, e.g. based on
tetraethoxysilane, epoxysilanes, such as
3-glycidoxypropyltrialkoxysilane, epoxides or oxetanes, amines,
quaternary amines, polyamines or quaternary polyamines, binders,
such as, for example, polyalkylene glycols, polyacrylates,
polyurethanes, polyesters, polyethers, polyamides or polyvinyl
alcohol, or additives which increase the conductivity, such as, for
example, polyalkylene glycols, in particular polyethylene glycols
or polypropylene glycols, polyglycerols or mixtures of these,
polyols, such as propylene glycol and ethylene glycol, sulphoxides,
such as dimethylsulphoxide, carboxylic acid amides, such as
methylacetamide, dimethylacetamide, dimethylformamide,
N-methylpyrrolidone, N-cyclohexylpyrrolidone, ionic liquids,
sugars, such as sorbitol.
The amount of these additives will of course depend on the nature
of the additive, but is usually in the range from 0 to 20 wt.-%,
more preferably from 1 to 15 wt.-% and most preferably from 2.5 to
10 wt.-%, based on the total weight of the composition.
Preferably, the composition according to the present invention
comprises, in each case based on the total weight of the
composition, I) 0.01 to 10 wt.-%, more preferably 0.1 to 7.5 wt.-%
and most preferably 0.5 to 5 wt.-%, of the conductive polymer; III)
0.01 to 10 wt.-%, more preferably 0.1 to 7.5 wt.-% and most
preferably 0.2 to 5 wt.-%, of the at least one compound according
to the present invention; IV) 0 to 20 wt.-%, more preferably from 1
to 15 wt.-% and most preferably from 2.5 to 10 wt.-%, of further
additives IV) being different from components I), II) and III),
wherein the reminder is the solvent II).
It is furthermore preferable for the composition according to the
present invention to have a pH in a range of from 1 to 12,
particularly preferably in a range of from 4 to 8, at a temperature
of 25.degree. C. The viscosity at 20.degree. C. of the composition
according to the present invention is preferably less than 1,000
mPas, preferably less than 400 mPas.
The solids content of the composition according to the present
invention is preferably in a range of from 0.1 to 10 wt. %,
particularly preferably in a range of from 0.5 to 7.5 wt. % and
most preferably in a range of from 1 to 5 wt. %.
The composition according to the present invention can be obtained
by various processes. According to a first embodiment, the
composition according to the present invention can be obtained by
oxidatively polymerizing the monomers used to prepare the
conductive polymer I), such as 3,4-ethylenedioxythiophene, in the
presence of the compound according to the present invention III) in
an appropriate solvent. The solvent used for the polymerization
reaction can be the solvent II) that is present in the composition
according to the present invention, however, it is also possible to
substitute the solvent used for the polymerization reaction by a
different solvent (such a process is disclosed, for example, in
U.S. Pat. No. 6,692,662 B2) or to add a further solvent to the
solvent used for the polymerisation reaction to obtain a solvent
mixture. According to a second (and preferred) embodiment, the
composition according to the present invention can be obtained by
simply adding the compound according to the present invention III)
to a composition that already comprises the conductive polymer I),
preferably to an aqueous PEDOT/PSS-dispersion. In this case it is
also possible that the solvent used for the polymerization reaction
can be the solvent II) that is present in the composition according
to the present invention or that the solvent used for the
polymerization reaction is substituted by a different solvent as
disclosed, for example, in U.S. Pat. No. 6,692,662 B2 or that a
further solvent is added to the solvent used for the polymerization
reaction to obtain a solvent mixture.
If necessary, the mixture of components I), II) and III) obtained
by one of the above mentioned processes is heated until all the
components are dissolved, wherein the maximum temperature will of
course depend on the boiling point of the solvent that is used.
A contribution towards solving the above mentioned objects is also
made by a process for the preparation of a conductive layer,
comprises the process steps: (P1) superimposing a substrate with
the composition according to the present invention or first
superimposing a substrate with a composition comprising the solvent
and the compound according to the present invention (but not
necessarily comprising the conductive polymer), at least partial
removal of the solvent and then superimposing the substrate with a
composition according to the present invention or with a
composition comprising the solvent and the conductive polymer (but
not necessarily comprising the compound according to the present
invention); or first superimposing a substrate with a composition
comprising the solvent and the conductive polymer (but not
necessarily comprising the compound according to the present
invention), at least partial removal of the solvent and then
superimposing the substrate with the composition according to the
present invention or with a composition comprising the solvent the
compound according to the present invention (but not necessarily
comprising a conductive polymer); (P2) at least partial removal of
the solvent.
In process step (P1) a substrate is superimposed with the
composition according to the present invention (or with a
composition comprising the solvent and either the conductive
polymer I) or the compound according to the present invention
III)). All layers which can be employed in electronic components,
such as, for example, in an OLED, are suitable as the substrate.
Thus, in particular, the substrate can be one which is furnished
with a preferably transparent base electrode, the substrate itself
preferably also being transparent. Glass, PET or other transparent
plastics, for example, can be employed as transparent substrate,
onto which a transparent electrically conductive electrode is then
introduced, such as e.g. an electrode made of indium-tin oxide
(ITO), doped zinc- or tin oxide or a conductive polymer.
Particularly suitable transparent plastic substrates are, for
example, polycarbonates, polyesters, such as e.g. PET and PEN
(polyethyleneterephthalate and
polyethylenenaphthalinedicarboxylate), copolycarbonates,
polyacrylates, polysulphones, polyethersulphones (PES), polyimides,
polyethylene, polypropylene, cyclic polyolefins or cyclic olefin
copolymers (COC), hydrated styrene polymers or hydrated styrene
copolymers. Suitable polymer bases can, for example, also be films
such as polyester films, PES films from the Sumitomo company or
polycarbonate films from the Bayer AG company (Makrofol.RTM.).
According to the invention, ITO coated glass is particularly
preferred as substrate.
Superimposing the substrate with the composition according to the
present invention or with a composition comprising the solvent and
either the conductive polymer or the compound according to the
present invention can then be accomplished by known methods, for
example by spin coating, dipping, pouring, dropping on, injecting,
spraying, knife application, spreading or printing, for example
inkjet, screen, intaglio, offset or pad printing, in a wet film
thickness of 0.1 .mu.m to 250 .mu.m, preferably in a wet film
thickness of 0.5 .mu.m to 50 .mu.m, and then dried at a temperature
of 20.degree. C. to 200.degree. C.
In process step (P2) the solvent that is contained in the
composition that has been applied is then at least partially
removed to obtain an electrically conductive layer comprising the
conductive polymer I) and the compound according to the present
invention III), said removal preferably being performed by simple
evaporation.
According to a particularly preferred embodiment of the process
according to the present invention process steps (P1) and (P2) are
is just two steps in the manufacture of an OLED. As stated above,
an OLED usually comprises an anode a hole injection layer an
emitter layer and a cathode,
wherein the hole injection layer is preferably prepared by the
process according to the present invention. The OLED may comprise
further layers, such as an electron injection layer that is located
between the electroluminescence layer and the cathode.
The OLED the hole injection layer of which has been prepared using
the composition according to the present invention can, for
example, exhibit any of the following layer structures (a) to (h):
(a) anode/ hole injection layer/ at least one emitter layer/
cathode; (b) anode/ hole injection layer/ hole transport layer/ at
least one emitter layer/ cathode; (c) anode/ hole injection layer/
at least one emitter layer/ electron injection layer/ cathode; (d)
anode/ hole injection layer/ hole transport layer/ at least one
emitter layer/ electron injection layer/ cathode; (e) anode/ hole
injection layer/ at least one emitter layer/ electron transport
layer/ cathode; (f) anode/ hole injection layer/ hole transport
layer/ cathode; at least one emitter layer/ electron transport
layer/ cathode; (g) anode/ hole injection layer/ at least one
emitter layer/ electron transport layer/ electron injection layer/
cathode; (h) anode/ hole injection layer/ hole transport layer/ at
least one emitter layer/ electron transport layer/ electron
injection layer/ cathode.
The layer structures (a) to (h) can be embodied either with the
anode located next to the substrate, the substrate being, for
example, glass or a transparent plastic film, or with the cathode
located next to the substrate.
The anode layer is preferably based on indium tin oxide, indium
zinc oxide, fluorine-doped tin oxide, tungsten trioxide, titanium
dioxide, molybdenum trioxide, aluminium zinc oxide, gallium indium
zinc oxide, aluminium, silver, palladium, copper, gold, platinum,
and alloys thereof, for example silver-palladium-copper and
molybdenum-chrome.
Suitable materials for the emitter layer are conjugated polymers
such as polyphenylenevinylenes and/or polyfluorenes, for example,
the polyparaphenylenevinylene derivatives and polyfluorene
derivatives described in WO-A-90/13148, or emitters from the class
of low molecular emitters, also termed "small molecules" in
technical circles, such as aluminium complexes, such as, for
example, tris(8-hydroxyquinolinato)aluminium (Alq.sub.3),
fluorescence dyes, e.g. quinacridones, or phosphorescent emitters
such as, for example, Ir(ppy).sub.3. Further suitable materials for
the emitter layer are described e.g. in DE-A-196 27 071.
Particularly preferred as emitter layer, according to the
invention, is tris(8-hydroxyquinolinato)aluminium (Alq.sub.3).
Preferred as the injection layer are single Ca layers or a stack
structure consisting of a Ca layer and another layer, which
consists of one or more materials selected from the group IA and
IIA metals of the periodic table, excluding Ca, which exhibit a
work function from 1.5 to 3.0 eV, and oxides, halogenides and
carbonates thereof. Examples of group IA metals of the periodic
table which exhibit a work function from 1.5 to 3.0 eV, and oxides,
halogenides and carbonates thereof, are lithium, lithium fluoride,
sodium oxide, lithium oxide and lithium carbonate. Examples of
group IIA metals of the periodic table, excluding Ca, which exhibit
a work function from 1.5 to 3.0 eV, and oxides, halogenides and
carbonates thereof, are strontium, magnesium oxide, magnesium
fluoride, strontium fluoride, barium fluoride, strontium oxide and
magnesium carbonate.
The electron transport layer can consist of materials such as, for
example, oxadiazol derivatives, anthraquinodimethane or derivatives
thereof, benzoquinone or derivatives thereof, naphthoquinone or
derivatives thereof, anthraquinone or derivatives thereof,
tetracyanoanthraquinodimethane or derivatives thereof, fluorenone
derivatives, diphenyldicyanoethylene or derivatives thereof,
diphenoquinone derivatives and metal complexes of
8-hydroxyquinoline or derivatives thereof, polyquinoline or
derivatives thereof, polyquinoxaline or derivatives thereof or
polyfluorene or derivatives thereof.
Particularly suitable materials for the cathode layer are
transparent or translucent materials with a relatively low work
function (preferably lower than 4.0 eV). Examples of this type of
material are metals, such as lithium (Li), sodium (Na), potassium
(K), rubidium (Rb), caesium (Cs), Be, magnesium (Mg), calcium (Ca),
strontium (Sr), barium (Ba), aluminium (Al), scandium (Sc),
vanadium (V), Zn, yttrium (Y), indium (In), cerium (Ce), samarium
(Sm), Eu, Tb and ytterbium (Yb); alloys consisting of two or more
of these metals; alloys consisting of one or more of these metals
and one or more metals selected from Au, Ag, Pt, Cu, manganese
(Mn), titanium (Ti), cobalt (Co), nickel (Ni), wolfram (W) and tin
(Sn); graphite or graphite intercalation compounds; and metal
oxides, such as, for example, ITO and tin oxide. Particularly
preferable is the use of aluminium as the cathode layer.
The application of the emitter layer, of the electron injection
layer and of the cathode injection layer can be carried out in a
manner known to a person skilled in the art, preferably through
vapour coating such as is described, for instance, in
WO-A-2009/0170244.
A contribution towards solving the above mentioned objects is also
made by a conductive layer comprising at least one compound
according to the present invention. According to a preferred
embodiment of the conductive layer according to the present
invention the conductive layer further comprises at least one
conductive polymer, wherein those conductive polymers are preferred
that have already been mentioned as preferred conductive polymers
I) in connection with the composition according to the present
invention. In this context it is also preferred that the weight
ratio of the at least one compound according to the present
invention and the at least one conductive polymer (in case of a
polythiophene/(poly)anion complex the weight ratio of the at least
one compound according to the present invention and the total
weight of polythiophene and polyanion) in the conductive layer is
preferably in the range from 1:100 to 100:1, more preferably in the
range from 1:10 to 10:1 and most preferably in the range from 1:5
to 5:1.
A contribution towards solving the above mentioned objects is also
made by a an electronic component comprising a conducting layer
obtainable by the process according to the present invention or
comprising a conductive layer according to the present invention.
According to a preferred embodiment of the electronic component
according to the present invention this electronic component is an
OLED, a display, an organic solar cell, a hybrid solar cell, a
field effect transistor, or a thermoelectric generator. In case of
an OLED it is furthermore preferred that the hole injection layer
of the OLED is obtainable by the process according to the present
invention or corresponds to a conductive layer according to the
present invention.
A contribution towards solving the above mentioned objects is also
made by the use of at least one compound according to the present
invention as an as an additive in a hole injection layer of an
OLED.
The invention will now be further illustrated by means of
non-limiting examples.
EXAMPLES
Example 1A Synthesis of Compound Xa
##STR00070##
Chromotropic acid disodium salt (2.00 g, 0.005 mol), potassium
carbonate (2.76 g, 0.005 mol), decafluorobiphenyl (8.35 g, 0.025
mol) and 50 ml of DMSO were stirred under heating at
120-130.degree. C. during 40 hours. The reaction was controlled by
.sup.1H-NMR spectroscopy. After completion of the reaction it was
cooled down to room temperature and filtered from the solid,
containing the rest of K.sub.2CO.sub.3 and the by-product KF. DMSO
from the filtrate was evaporated under vacuum (1 mbar) and excess
of decafluorobiphenyl was sublimed. 20 mL of water were added to
the residue and the product was precipitated as a white solid,
which was filtered and washed with cold water. The filter cake was
dried under vacuum to give 2.27 g of the pure compound Xa, which
correspond to the isolated yield of 69%.
.sup.1H NMR (300 MHz, DMSO-d6) .delta.=8.12 (s, 2H), 7.65 (d,
J=15.9 Hz, 2H); .sup.19F NMR (282 MHz, DMSO-d6) .delta.=-55.6 (m),
-59.5 (m), -60.2 (m), -70.0 (m), -78.7 (m), -82.7 (m).
Prior to formulation compound Xa was recrystallized. It was
dissolved in H.sub.2O (solid content 1%) and heated to 90.degree.
C. The hot solution was filtered through a syringe filter (PVDF,
0.8 .mu.m) and concentrated.
Example 1B Synthesis of Compound Xe
##STR00071##
3,6-Dihydroxynaphthalene-2,7-disulfonic acid disodium salt was
reacted with hexafluorobenzene and potassium carbonate (1:4:10 mole
ratio) in DMF (at concentration of 40 g of
3,6-dihydroxynaphthalene-2,7-disulfonic acid disodium salt per 1 L
of DMF) at 130.degree. C. The reaction was controlled by
.sup.1H-NMR spectroscopy. After 20 h of heating at 120-130.degree.
C. the reaction was complete according to .sup.1H-NMR spectroscopy.
The mixture was cooled to room temperature and filtered from the
solid, containing the rest of K.sub.2CO.sub.3 and the by-product
KF. DMSO and the excess of hexafluorobenzene from the filtrate were
evaporated under vacuum (1 mbar). Water (10 mL per 25 mL of the
initial amount of DMSO) was added to the residue and the product
was precipitated as a white solid, which was filtered, washed with
water and dried under vacuum (1 mbar) to give the first portion of
compound Xe. The filtrate formed was evaporated up to approximately
50% of its initial volume and cooled overnight in the refrigerator
at 4.degree. C. A new portion of the product was precipitated as a
white solid, which was filtered again, washed with water and dried
in vacuum (1 mbar) to give the second portion of compound Xe as a
white solid. The total yield of compound Xe was 67%.
.sup.1H NMR (300 MHz, DMSO) .delta. 8.31 (s, 2H), 7.07 (s, 2H);
.sup.19F NMR (282 MHz, DMSO) .delta.=-76.0 (m), -83.0 (m), -84.3
(m).
Example 1C Synthesis of Compound Xg (Soluble in Organic
Solvents)
##STR00072##
K.sub.2CO.sub.3 (1.1 g, 0.008 mol) and decafluorobiphenyl (3 g,
0.009 mol) were suspended in dry N,N-dimethylacetamide (10 ml) and
heated to 100.degree. C. 1,3,5-Trihydroxybenzene (0.25 g, 0.002
mol) dissolved in DMAc (10 ml) was added slowly over a period of 4
h at 92-97.degree. C. After complete addition the reaction mixture
was heated to 120.degree. C. until TLC confirmed complete
consumption of starting material. The mixture was concentrated and
to the residue a dilute NH.sub.4Cl-solution (1 g NH.sub.4Cl/20 ml
H.sub.2O) was slowly added. The aqueous phase was extracted 3 times
with MTBE. The combined organic layers were washed with brine and
dried over Na.sub.2SO.sub.4. After evaporation of solvents the
clear yellow highly viscous oil was purified by column
chromatography over SiO.sub.2 (eluent: toluene). The product was
isolated as a light yellow highly viscous oil (2.1 g, 0.002 mol,
quant.).
LC-MS (ESI; H.sub.2O/MeCN Grad. 0.8 g/L NH4OAc) M=1068; .sup.1H NMR
(400 MHz, CDCl.sub.3): .delta.=6.49.
Example 2
Formulation of a Dispersion of PEDOT:PSS with Compound Xa
##STR00073##
Example 2A (Solid Content of Compound Xa=0.7%)
0.42 g of compound Xa were dissolved in 30 g Clevios P VPAI 4083
(Heraeus Precious Metals GmbH & Co. KG, 1.5% solid content). 24
g of water were added and the mixture was stirred for 30 min at
room temperature and then heated (1 h, 40.degree. C.) until all
solids were dissolved completely. The mixture was cooled to room
temperature (1 h), 6 g of ethanol were added and the mixture was
stirred for another 30 min. After aging for 3 h the dispersion was
filtered subsequently through 0.8 .mu.m and 0.45 .mu.m syringe
filters (PVDF).
Example 2B (Solid Content of Compound Xa=0.47%)
0.28 g of compound Xa were dissolved in 40 g Clevios P VPAI 4083
(Heraeus Precious Metals GmbH & Co. KG, 1.5% solid content). 14
g of water were added and the mixture was stirred for 30 min at
room temperature and then heated (1 h, 40.degree. C.) until all
solids were dissolved completely. The mixture was cooled to room
temperature (1 h), 6 g of ethanol were added and the mixture was
stirred for another 30 min. After aging for 3 h the dispersion was
filtered subsequently through 0.8 .mu.m and 0.45 .mu.m syringe
filters (PVDF).
Example 2C (Solid Content of Compound Xa=0.3%)
0.18 g of compound Xa were dissolved in 40 g Clevios P VPAI 4083
(Heraeus Precious Metals GmbH & Co. KG, 1.5% solid content). 14
g of water were added and the mixture was stirred for 30 min at
room temperature and then heated (1 h, 40.degree. C.) until all
solids were dissolved completely. The mixture was cooled to room
temperature (1 h), 6 g of ethanol were added and the mixture was
stirred for another 30 min. After aging for 3 h the dispersion was
filtered subsequently through 0.8 .mu.m and 0.45 .mu.m syringe
filters (PVDF).
Example 2D (Solid Content of Compound Xa=1.05%)
0.63 g of compound Xa were dissolved in 30 g Clevios P VPAI 4083
(Heraeus Precious Metals GmbH & Co. KG, 1.5% solid content). 24
g of water were added and the mixture was stirred for 30 min at
room temperature and then heated (1 h, 55.degree. C.) until all
solids were dissolved completely. The mixture was cooled to room
temperature (1 h), 6 g of ethanol were added and the mixture was
stirred for another 30 min. After aging for 3 h the dispersion was
filtered through a 0.8 .mu.m syringe filter (PVDF). For filtration
through 0.45 .mu.m syringe filter 3 h ultrasonic treatment (Sonorex
R1028, Bandelin) was necessary prior to filtration.
Example 3
Fabrication of an OLED with a Conductive Layer Containing Compound
Xa
The dispersion obtained in Examples 2A-2D was used to construct
organic light emitting diodes (OLEDs). The procedure for producing
the OLEDs was as follows:
i) Preparation of the Substrate ITO-coated glass is cut into pieces
50 mm.times.50 mm in size (substrates) and is structured with photo
resist into 8 contact lines--each 2 mm in width at their ends.
Thereafter, the substrates are cleaned in 0.3% strength Mucasol
solution in an ultrasound bath, rinsed with distilled water and
spin-dried in a centrifuge. Immediately before coating, the
ITO-coated sides are activated for 10 min in a UV/ozone reactor
(PR-100, UVP Inc., Cambridge, GB).
ii) Application of the Hole-Injecting Layer About 5 ml of the
dispersion according to Examples 2A-2D are filtered (Millipore HV,
0.45 .mu.m). The cleaned ITO-coated substrate is laid on a
spin-coater (Carl Suss RC8) and the filtered solution is
distributed on the ITO-coated side of the substrate. The excess
solution is then spun off by rotating the plate for 30 sec. The
spin-speed was adjusted to obtain always a layer thickness of 50 nm
(dried film) determined with a stylus profilometer (Dektak 150,
Bruker). Thereafter, the substrate coated in this way is dried on a
hotplate at 200.degree. C. for 5 min.
iii) Application of the Hole Transport and the Emitter Layer The
ITO substrates coated with the dispersion from Examples 2A-2D are
transferred into a vapor deposition unit (Univex 350, Leybold).
Under a pressure below 10.sup.-3 Pa, first 60 nm of a hole
transport layer of NPB
(N,N'-bis(naphthalen-1-yl)-N,N'-bis(phenyl)-benzidine) and then 50
nm of an emitter layer of AlQ3
(tris-(8-hydroxyquinoline)-aluminium) are vapor-deposited in
succession at a vapor deposition rate of 1 .ANG./sec.
iv) Application of the Metal Cathode The layer system is then
transferred into a glove box with an N.sub.2 atmosphere and an
integrated vapor deposition unit (Auto306 Vacuum Coater, Edwards),
and metal electrodes are vapor-deposited. For this, the substrate
is laid on a shadow mask with the layer system downwards. The
shadow mask comprised rectangular slots of 2 mm width which
intersected the ITO strips and are orientated perpendicular to
these. A 0.5 nm thick LiF layer and then a 200 nm thick Al layer
are vapor-deposited successively from two vapor deposition boats
under a pressure of p<=10.sup.-3 Pa. The vapor deposition rates
were 1 .ANG./s for LiF and 10 .ANG./s for Al. The area of the
individual OLEDs is 4.0 mm.sup.2.
v) Layer Stack Overview
Example 3A ITO//Formulation from Example 2A (50
nm)//NPBNALQ//LiF//Al
Example 3B ITO//Formulation from Example 2B (50
nm)//NPBNALQ//LiF//Al
Example 3C ITO//Formulation from Example 2C (50
nm)//NPBNALQ//LiF//Al
Example 3D ITO//Formulation from Example 2D (50
nm)//NPBNALQ//LiF//Al
vi) Characterization of the OLED The two electrodes of the organic
LED are connected (contacted) to a source/measuring unit (Keithley
2400) via electrical leads. The positive pole is connected to the
ITO electrode and the negative pole is connected to the metal
electrode. The dependency of the OLED current and the
electroluminescence intensity (detection is with a photodiode
(EG&G C30809E)+electrometer (Keithley 6415)) on the voltage is
plotted. The lifetime of the OLED-device is then determined by
allowing a constant current of I=3.84 mA to flow through the
arrangement and monitoring the voltage and light intensity as a
function of time. The characteristic Data for the OLEDs is
summarized in table 1.
Comparative Example 4
Fabrication of an OLED not Containing Compound Xa
The procedure is the same as in Example 3, with the difference that
in the second process step Clevios P VP AI4083 (Heraeus Precious
Metals GmbH & Co. KG), regarded as standard in OLED
construction, was used solely as the interlayer instead of the
dispersions according to the invention from example 2A-2D.
Clevios.COPYRGT. P VP AI4083 was deposited according to Example 3.
The film thickness was 50 nm.
The characteristic Data for the OLEDs is summarized in table 1.
Layer Stack:
Comparative Example 4
ITO//Clevios P VP AI4083 (50 nm)//NPB//ALQ//LiF//Al
Example 5
Determination of Resistivity
The resistivity of Clevios.TM. films is determined by measuring the
film's sheet resistance and its layer thickness. The films are
prepared by depositing 1-2 ml of the polymer dispersion on a 50
mm.times.50 mm glass-substrate. Prior deposition the
glass-substrate of 1 mm thickness is thoroughly cleaned in 0.3%
strength Mucasol solution in an ultrasound bath, rinsed with
distilled water and spin-dried in a centrifuge. As a final step the
surface to be coated on is activated by UV/Ozone exposure
(PR-100UV/Ozone UVP, Cambridge, GB) for 15 min. Next the
glass-substrate is placed in a chuck of a spin-coater (Carl Suss
RC8). The overlaying dispersion is removed by rotating the
glass-plate at 1000 rpm for 30 sec. A thin uniform film is
obtained. The film is conveyed to a heat-plate set to 130.degree.
C. and left there for 5 min to dry.
In a next step the film is covered with a shadow mask. The mask is
made of a 100 .mu.m-thick steel-sheet of size 50 mm.times.50 mm
exhibiting 6 parallel slits machined in the centre (Length L: 25.0
mm, width b: 3.0 mm, slit-separation: a=500 .mu.m). The mask is
held by a magnet from the backside of the coated substrate. The
substrate is mounted in a vacuum-evaporator with electro-thermally
heated boats for Ag-evaporation (Univex 350, Leybold). The vessel
is evacuated to a pressure of 6.times.10.sup.-4.degree. Pa. When
this pressure is reached, Ag is thermally evaporated at a rate of
20 .ANG./sec until a final electrode-thickness of 2000 .ANG. is
reached.
The resistance R between adjacent Ag-electrodes is measured with an
electrometer (Keithley 616) in a home-built set-up in which the
sample is mounted in a vacuum chamber and Au-contact pins are
pressed on the Ag-electrodes.
The film's thickness d is determined by scratching the film off the
substrate with a razor blade and scanning the stylus of a
mechanical profilometer (Dektak 150, Bruker) across the
scratch.
Finally the resistivity "ro" is calculated my multiplying the sheet
resistance with the layer thickness according to
ro=R.times.L/b.times.d.
The resistivities of films made of dispersions according to Example
2A-2D are shown in table 1.
Example 6
Comparison of the OLEDs from Examples 3 and 4
The graphs plotting current and electroluminescence against voltage
and the lifetime measurements for the OLEDs from Examples 3 and 4
were compared.
TABLE-US-00001 TABLE 1 OLED-characteristics from Examples 3 and 4
wherein the values were normalized to the comparative example 4.
IVL-Characteristics at specific U = 5.0 V Lifetime @ I = 48
mA/cm.sup.2 resistance I L Efficiency U (t = 0) L (t = 0) t (80%) t
(50%) (Ohm .times. cm) (mA/cm.sup.2) (cd/m.sup.2) (cd/A) (Volt)
(cd/m.sup.2) (h) (h) Ex. 3A 0.13 1.48 1.58 1.05 0.90 1.01 2.2 2.6
Ex. 3B 0.11 1.33 1.24 0.93 0.95 0.93 2.79 2.94 Ex. 3C 0.1 1.3 1.34
1.03 0.90 0.92 2.2 2.18 Ex. 3D 0.1 1.5 1.72 1.14 0.89 1.01 1.8 2.57
Comp. Ex. 4 1 1 1 1 1 1 1 1 (AI4083)
A significant increase of lifetime compared to the standard
(Comparative Example 4) can be observed for all Examples 3A-3D.
* * * * *